【摘要】 在三正辛基氧化膦(TOPO)-乙酸乙酯体系中,应用氯化亚锡活化-溶剂萃取技术选择性分离Rh(Ⅲ)和Ir(Ⅳ),通过萃取铑实现铑铱的分离。考察了nSn/nIr、盐酸浓度对铱萃取率的影响。在相比为1∶1,nSn/nIr(nSn/nRh)=4,3 mol.L-1盐酸浓度的条件下,通过对含不同浓度铑、铱的料液进行萃取,铑的萃取率达到98%以上,铱的萃取率低于4%。在萃取过程中未能完全分离的铑铱通过HCl与KClO3的混合溶液以及硝酸的反萃实现分离。研究了贱金属的萃取行为,考察了贱金属及金对铑铱萃取分离的影响。将饱和萃取有机相减压蒸馏,通过红外光谱表征,探讨了萃取机理。更多还原

【Abstract】 The separation of Rh(Ⅲ) and Ir(Ⅳ) from the stannous chloride medium by extraction of rhodium with trioctylphosphine oxide(TOPO) was studied.It is based on the fact that a bi-nuclei bridged complex anions of the form[Rh2Cl6-n(SnCl3)n]4-(n=2-4) could be extracted rapidly by TOPO,while IrCl2-6 remained in the organic phase.The effects of Sn/Ir molar ratio and hydrochloride concentration on the extraction of iridium were studied.The optimal conditions were as follows: phase ratio,1∶1;Sn∶Rh and Sn∶Ir molar ratios,4;cHCl,3 mol·L-1.Under the optimal extraction conditions,the percent extractions of Rh and Ir were more than 98% and less than 4%,respectively.The rhodium and the iridium which were not separated in the extraction process could be stripped by a mixed solution of HCl with KClO3 and nitric acid,respectively.The extraction behavior of base metal was studied and the result indicated that the effect of base metal must be taken into consideration in the separation process.Extraction complex obtained from the saturated organic phase was analyzed by FT-IR spectra and the extraction mechanism was discussed.更多还原